/Engine/Plugins/Runtime/Metasound/Source/MetasoundGenerator/Public/MetasoundGenerator.h
In order to useFNameas a key to aTSortedMapyou have to explicitly choose which comparison implementation you want to use. Declaring the type here helps minimize the confusion over why there are so many template arguments.
typedef [TSortedMap](API\Runtime\Core\Containers\TSortedMap)< [FName](API\Runtime\Core\UObject\FName), [FParameterSetter](API\Plugins\MetasoundGenerator\FParameterSetter), FDefaultAllocator, [FNameFastLess](API\Runtime\Core\UObject\FNameFastLess) > FParameterSetterSortedMap